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The year was 1946. The Second World War had just ended. It was the dawn of a new age on Earth.

The victorious Allies, led by the United States, the United Kingdom, the Soviet Union, France and China, had assembled themselves in what would be known as the United Nations, so that all of the world could be at peace. People looked at the future with hope, having witnessed first hand the horrors of the War.

That, unfortunately, would prove not to be the case. The world was now split into two, under the shadow of the USSR to the East, and the US to the West. Yet, no matter the political differences, the remaining superpowers, the US, the UK, and the USSR in particular, symultaneously turned their eyes skywards: the future laid not on brown soil, but in the blue skies above.

True powered aircrafts had been born just forty years before, but now they bore little, if any, resemblance to the Flyer built by the Wright brothers, and there were rumors about an American prototype which was capable of going past the Columns of Hercules of Aviation: the sound barrier. But, while aircrafts were the big thing for the general public, a small, if resolute, group of scientists and engineers had their focus on another marvel of technology: the rocket.

The history of rocketry had started many centuries before in China, but the most important advancements had been made much more recently. It was almost universally agreed, however, that the greatest pioneer was Kostantin Tsiolkovsky, a native Russian, whose ideas on rocket propulsion and propellants, but most importantly, his equations, had laid unknown for quite some time. In the US, during the 1920s, the famous inventor Robert Goddard had developed, and launched, the first ever liquid propelled rocket.

In Germany the Verein für Raumschiffahrt (VfR, of Society for Space Travel) had had some significant developments as well, in particular regarding the use of Liquid Oxygen and Ethanol as propellants, before dissolving in 1934. In the Soviet Union there had been numerous inventors, notably Valentin Glushko, whose team conducted hundreds of tests, but the Purges of the late '30s soon put an end to these experimentations.

During World War Two rockets were used by almost every party, mostly for battlefield-level weapons, such as the Rocket Anti-Aircraft Artillery of the Royal Navy, or the Katyusha rockets of the Soviets. But the most interesting, and fundamental, designs came from the United States and pedant Germany.

In Germany, the infamous V-2 rocket had been developed and fielded during the war by a team headed by Wehrner von Braun, who was later extradited to the US along with most of his team. It was a most revolutionary design, a "ballistic missile", capable of a range of 300km, hitting, albeit with disputable results, the British mainland. These rockets had very advanced features such as HTP-driven turbopumps, and inertial guidance. Even further, these rockets scraped the edge of space on their way to London.

In the US, while no actual full scale testing took place, there was a much more ambitious program. Developed in complete secret under the codename Project Prometheus, the initial plans called for a two-stage rocket, large enough to throw a (theoretical, at the time) 7000kg nuclear bomb across the ocean, in the instance of British surrender and/or full Soviet control of the European mainland. While this concept never came to be, a series of scale motors were built, and this experimentation meant that an experienced team was readily available in the US for subsequent programs.

In late 1947, however, the unexpected happened. This team of American engineers, now joined by the Germans under von Braun, was approached by a British organization, who wished to join their forces in pursuit of a greater goal: exploring space. The project was left off to rust for quite some time, but, following several years of negotiations, of course keeping the public in the dark, the plans were approved and signed by future Administrators Sir Philip Perrington and General Garrett H. Woodward. Finally, on December 19th, 1950, the International Rocket Society came to be.

Chapter III: Reaching for the Stars
XXVIII: Reaching for the Stars, Part 1
XXIX: This Side of Paradise, Part 5
XXX: Reaching for the Stars, Part 2
XXXI: Reaching for the Stars, Part 3XXXII: Reaching for the Stars, Part 4
XXXIII: The Way to Progress, Part 2

Useful Information:

What is this about?

Beyond Earth is an alternate space race set on an Earth whose history is very similar to ours until just after World War Two. Of course, divergences occurred even before (think of Project Prometheus), but the point at which the differences really start to matter is in 1946-1947, as I've explained in the introduction.

The story will be narrated from a Western perspective, which means little to nothing is known about the Soviet (and later, the Chinese) Space Program. I chose this approach mainly because this is RP-1, and it would be somewhat difficult to manage completely different programs at the same time. I will, however, still try to make the story as interesting as possible.

About myself:

Well, what can I say. I'm Fenisse, or Danilo, I'm from Italy, and I'm not really new to the Forums, but as I haven't posted in quite a while I guess many may not know me (not that I was that famous before, to be honest). Anyways, I've been playing the Realism Overhaul suite for quite some time (basically, since it was first created), although I only recently started playing KSP again. I figured I could share with you my new RP-1 campaign, while adding a (somewhat) interesting backstory to it. I have previously played a RP-0 campaign on KSP 1.0.4 and later 1.0.5 (you can find the imgur album here), and later took part in the Go For Launch project all the way back in 2016.

I wanted to excuse myself beforehand for the fact I won't be posting updates that often (schedules may vary greatly), due to university and other messes i could get into. I want to take my time so that every "chapter" is as polished as possible. I have, however, prepared in advance lots of material for the first couple of chapters, which now only need to be written.

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The International Rocket Society’s early moments were not easy at all. It was like having a giant sit on a chair made of toothpicks; the future of this undertaking was uncertain at best. The main issues were with reciprocal distrust between the British and American governments: while the scientist and engineers (and to some extent, even the chairmen) were more than happy to work together, the politicians thought of the Society as nothing more than another nuisance, and a possible source of state secrets leaks, especially now that relations with the Soviets were crumbling. Nonetheless, work proceeded as planned despite the very limited funding received, and the IRS was allowed to test its designs at the Cape Canaveral AFS in Eastern Florida.

The Americans and British had different areas of expertise: extensive rocket development had given the US a thorough understanding of rocketry, even more so with the addition of the Germans (who had been reluctantly “leased” by the Army to the IRS), while restrictions and even bans had made life difficult for rocket engineers in Britain, however, they possessed extensive knowledge about jet engines and high-speed flight, which would certainly prove useful sometime later. The teams also agreed to use the metric system, which caused somewhat of an uproar, due to ease of conversions.

The first objective of the Society was finding a reliable and economically feasible way to access the secrets of space, which meant designing a new sounding rocket. Unfortunately, due to budget shortages, the IRS could not develop anything anew (although the British had been planning something for quite sometime as of now), so they had to go with existing technology for the time being.

The obvious choice was to keep using what the US had been using for the last five years or so: the WAC-Corporal and the A4. There were problems with the A4, however: the technology was itself very old and relatively unreliable, and there remained few rockets due to extensive testing and no production of the rocket occurring in the post war years.

The WAC-Corporal, on the other hand, had been refined over the course of its service life, and by the time they got into the IRS’s hands, most of the problems had been solved. The Society, however, desired to achieve better results with the WAC-Corporal, therefore determining to develop their own version of the missile. It wasn’t much different from the original, just stretched and with better materials that were just becoming available to support the longer burn time. The IRS designated this rocket as the WAC M1951-A0504, or simply the WAC.

WAC Blueprint, cost is in 1951 US dollars.

The booster stage was a Tiny Tim solid rocket motor, developed as a weapon for the US Navy in WW2. It provided the rocket with enough thrust to propel it to around 500 meters altitude, which made it pick up speed while the WAC motor was still igniting. The sustainer stage ignited at liftoff and reached full thrust around 0.5 seconds later, and it separated from the Tiny Tim around one second after lift off. The boost phase lasted for 90.1 seconds, which brought the rocket to around 25km, and it then coasted to apogee. At apogee, the payload compartment (above the despin module) separates and the parachute arms. What is left of the WAC then lands safely about two minutes later.

The burn time of the upgraded WAC-Corporal motor, still using the same Aniline/Furfuryl/IRFNA-III mixture of the original design, was really pushing it, and many feared it would simply burn through and/or explode in the last part of the flight. The general payload carried was a high-altitude package to study the atmosphere above the mesosphere.

The first flight of the WAC (WAC-1) took place on March 6, 1951 at Cape Canaveral. It was a disappointing failure: the Tiny Tim booster worked perfectly, but the Upgraded WAC did not ignite, leading to the rocket crashing near the launch site a few seconds later. This failure had a heavy impact on the already unpopular reputation of the IRS among the top brass, who were already planning on shutting down the project for good.

Despite the setback, the engineers didn't let themselves get let down, instead seeing the failure as an opportunity to improve, and moreover, the knowledge gained would certainly prove useful at some point in the future. Due to the fact the motor didn't ignite at all, the WAC reached about 2km altitude or so before it started to come down, therefore the speed as it touched the ground wasn't very high, and much could be learnt by doing an autopsy of the engine assembly. The investigation revealed that the IRFNA-III valve didn't open due to a short circuit, and of course without the oxidizer the reaction couldn't have happened. The same issue was found on the next WAC scheduled for launch but was readily solved, and just two months after the failure of WAC-1, the IRS was ready to launch another rocket.

The second flight (WAC-2), which occurred on May 9, 1951, was a complete success: the rocket worked perfectly with clean (for the time) combustion occurring until the very end of the boost phase. Telemetry worked perfectly up until the altitude of around 50km, but after that the results were very erratic and therefore the actual altitude reached could not be determined with precision, but it was probably above 90km, due to the detection of rising temperatures caught by the thermometers aboard.

The third launch (WAC-3) on June 25, 1951 finally determined the maximum apogee reachable by the WAC: an extraordinary 93km, which was made more impressive by the fact that the WAC carried a heavy, 94kg or more of payload. The results of the scientific experiments were consisted with what was expected by a flight in the lower thermosphere, and the payload was recovered successfully.

There was a fourth flight (WAC-4) on August 8, 1951 which ended in a partial success due to a loss of performance from undetermined causes (it was speculated it was due to burn through of the rocket nozzle) in the last three seconds of the boost phase, nevertheless the rocket reached an altitude of 87km, which was more than enough to run the required experiments.

A fifth launch (WAC-5) was scheduled to occur later the same year, but it was cancelled due to the fact the first models of IRS Aerobees were finally being manufactured to be launched before the end of 1951, and by reason of the much better capabilities of these advanced rockets, WAC-5 was never to take place.

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The WAC sounding rocket was a very good vehicle for its capabilities, but it had a severe weakness: its maximum altitude of 93km was not enough to cross the Karman line and effectively enter space. While this deficiency would be rectified by the WAC successor, the Aerobee, the International Rocket Society needed a vehicle capable of reaching space in the interim. The only rocket available to the IRS at the time that had those specifications was a relic of the Second World War: the A4 rocket.

The history of the A4 began many years before, in Germany. A young Wehrner von Braun had caught the eye of the German military staff, he was appointed to a solid rocket research facility in Kummersdorf, and later the Army Research Center in Peenemunde. He and fellow engineer Walter Riedel soon started to design the Aggregat series of rockets, which was to culminate in a huge rocket with a thrust of more than 25,000kg. Early testing using scale models in 1936 would unfortunately prove unsuccesful, postponing the development of the full-scale rocket, the Aggregat 4. Therefore deals were made with universities to solve the Aggregat family issues, and by 1941 the technology to ensure the A4's success was available. The rocket's first flight took place in 1942, and in 1944 it was first deployed for combat operations. Now known as the V2, a weapon of vengeance, these rockets soared the skies, scraping the edge of space as they fell upon British and Belgian cities.

After the end of the War, many A4s were recovered by the US, the UK and the Soviets, and extensive research took place in those countries. In the US, the failure of Goddard's Project Prometheus to produce any results meant that the A4 was to be used in high altitude tests. The presence of Wehrner von Braun further influenced American rocketry, and many future designs bore some resemblance to the old ballistic missile.

By the time the International Rocket Society got its hands on the A4s, in June 1951, the missiles still available for testing were really showing their age. Therefore, a lenghty and thorough process of refurbishment took place, and by early October two of the rockets were ready for use, and another three were still being refurbished.

Schematic of the A4, cost in 1951 US dollars.

The A4 was ignited three seconds before lift-off, to allow the engine to achieve full thrust. The A4 motor was different from the WAC, the latter was pressure fed and did not require a turbine, the former used an external HTP tank to power the turbines, which take some time to get to full speed. The rocket burned a 51/48% mixture of 75% Ethanol and Liquid Oxygen, which meant the combustion chamber reached temperatures in the degree of 2700K. To solve this issue the alcohol fuel was pumped along the double wall of the main combustion burner, heating the fuel and cooling the combustion chamber. Small holes also permitted some alcohol to escape directly into the chamber, forming a boundary layer that further protected the wall of the chamber. This layer ignited on contact with the atmosphere, explaining the rocket’s diffuse exhaust plume.

The first launch of an IRS A4 occurred on October 21, 1951. The mission, named A4-1, was intended to send a scientific payload much similar to that of the WAC, albeit heavier and therefore with more precise instruments. Although the payload bay had been modified to allow for a (relatively high-resolution) camera to be on board, for this flight it wasn’t present. The weight of the instrument was covered by ballast.

The flight went very smoothly. The boost phase was uneventful, the rocket passing through max Q without any issue whatsoever, and the engine burned all of the propellant to the last drop. The instruments were active from just before lift-off to a little over three minutes later when the batteries ran out. At the end of the coasting phase, the rocket had reached an altitude of 190km. It fell into the Atlantic Ocean shortly thereafter.

The mission was a success. While the A4 test was meant to be more of a stopgap measure as the first Aerobee were rolled out, it was quite the story indeed. The US Army was much more eager to cooperate with the IRS, seeing it as an opportunity to develop technology in parallel, the same couldn’t be said of the Navy or the Air Force, who’d rather stick to their own business. The Royal Air Force as well praised the IRS for the successful launch.

The success of this mission also provided Von Braun with the opportunity to press forward his grand plan of expanding the Aggregat family. On a November day he met with the Administrators at Cape Canaveral. He presented them with some papers, including the sketch below.

His plans called for the development of an upgraded A4 engine called the A9. Instead of using 75% Ethanol as fuel, he suggested developing a hypergolic mixture of to be determined chemicals. The new engines would have less thrust than the Ethanol ones, but also came with a considerable increase in specific impulse.

The A9 stage was mostly meant as an upper stage, although it could also be flown at sea level. It was to be tested in the first phase of the Aggregat expansion project. The second phase of the program involved the development of the A10 stage, to be mounted below the A9 in what was called the A10/A9. The third and last phase of the project concerned the development of the A11 stage (not represented), the lower stage of the 200 tons A11/A10/A9 rocket, which would be capable of putting from 0.5 to 1 metric ton of payload into orbit around the Earth by 1955 or even 1954.

The proposal was certainly interesting, but the administrators decided not to give the go ahead, due to the possible improvements in technology making the A9 engine obsolete by the time it came out, and the absurd costs of building a 200 metric tons launch vehicle and the facilities to support it.

It was better to go forwards one step at a time, and the next step would be taken not long thereafter: the first IRS Aerobee was just rolling out of the assembly plant.

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The WAC by 1951 had exhausted its purpose, but during its numerous years of service had earned the respect of engineers and white collars alike. The first step forward was just being taken: on December 4th, 1951 the first IRS Aerobee was completed at the assembly plant.

The Aerobee rocket had actually been developed in the US many years earlier, for reasons similar to those that prompted the IRS to develop its own version: limited supply of A-4s and the desire to achieve similar results at a much lower cost. Designed by James Van Allen and Rolf Sabersky in a joint venture of the Applied Physics Laboratory and the Aerojet Corporation, with support from the US Navy. The first Aerobee was launched in 1947.

The IRS Aerobees came at a much later date, and advancements in rocket propulsion and construction had been made. Therefore, these versions of the Aerobee came to differ somewhat (yet still bearing a strong resemblance) from their American cousins.

IRS Aerobee 1 schematic, showing the whole rocket assembled and then a detail of the booster stage.

The Aerobee I was made of two stages, a booster (IRS-2.5KS) and a sustainer (IRS-XASR-1A), as was the case for the WAC. The booster stage was made of an Aerojet X103C10 (2.5KS18000), which was a huge improvement over the “Tiny Tim” of the WAC. The solid motor burned for about 4.1 seconds, after which time it would be jettisoned.

Most of the kick was provided by the sustainer stage, the IRS-XASR-1A. Ignited at liftoff, it used a XASR-1 engine (hence the designation) burning for around 1 minute, and providing about 2500 m/s of delta V, the number varying depending on the payload. The propellants were the same, Aniline/Furfuryl and IRFNA-III, but the mixture was different, with a much higher IRFNA percentage, at around 62%. The increased thrust and efficiency of the engine, along with the more powerful booster stage, meant that the new Aerobee could reach altitudes which before necessitated an A-4.

The most important improvement from the WAC was however the cost: it had been cut by more than half, and streamlined production methods allowed for far quicker construction and assembly of the rocket.

The first flight of an Aerobee (Aerobee-0T) took place on December 13th, 1951. It was only meant as a test flight, so it carried no real payload other than the telemetry transponder. The rocket took off at about 11 in the morning, and the flight was a complete success: the rocket reached an impressive apogee of 239km, much higher than that of both the WAC and the A-4. Being a test flight, the rocket lacked any sort of parachute, and as such it was destroyed on impact.

There was a second flight (Aerobee-1) on December 29th, 1951 which also was a success. It carried a cosmic ray payload to 221km, but other than that the flight was not really interesting.

The third flight (Aerobee-2), on January 15th, 1952, on the other hand, proved to be quite the opposite. Among the scientific payload it also carried a small camera, designed to take a photo as soon as the rocket approached apogee. While certainly not the first photo of Earth from space, it was nonetheless remarkable, especially considered the limited size and weight of the camera. Many newspapers talked about it, even making first page on some.

Image 19520115A, an image of Earth from space and also cover poster of this thread. [AUTHOR'S NOTE: photos are labelled YYYYMMDDx, with x being a letter or multiple letters in alphabetical order]

There was a fourth flight (Aerobee-3) on January 31st, 1952, carrying an atmospheric analyzer payload to 220km, but as with Aerobee-1, there wasn’t much to be said about it, other than it was a success.

The fifth launch (Aerobee-4) on February 16th, 1952 was somewhat more interesting for two main reasons: it carried the heaviest payload to date, nearing the maximum capacity of the payload bay; and a photograph of the rocket was taken by a journalist just before launch. This was the first time that an IRS rocket was photographed, which showed the advancements in public relations made over the last year.

Image 19520216A, taken by CBS photographer Danny Brewer, who would later become an habitué at the IRS.

As of late February 1952, the Aerobee program had been a resounding success. Not only had it broken several records and increased the IRS’s scientific capabilities, but it had also caught the eye of several private contractors (mainly universities), while at the same time building the foundations for a long-lasting partnership with Aerojet. Of course, media relations had also greatly improved, and the general populace was now aware of the Society and its goals.

But March 1952 wouldn’t be another month of scientific Aerobee launches. The British had been planning something all along, and on February 24th they finally announced their project to the world: Project Thunder, with the goal of developing cutting-edge supersonic aircraft technology.

Author's note: I originally intended to post this update on the 31st (Italian time, obviously), so that I could wish you a Happy New Year. Unfortunately, a series of events led to me being unable to complete the last paragraph and the schematic in time. I instead will post them now (it is noon here as I'm writing), on January 1st.

I wish you all the best for 2019, and I wanted also to thank you for the support I've received, I couldn't have even fathomed a similar response. I hope I will be able to continue the project even in this new year, and hopefully receive some criticism on how to produce content more to your liking. I obviously won't change the basic structure of my posts, but still, if you can think of something that I may add, please tell me.

By the way, as the complexity of launches and missions increases, I have decided to add some sort of "simulations", that is screenshots of the game without making them look like photographs that would fit the time period. I think that would make missions such as satellite launches and interplanetary probes more interesting, instead of just being a wall of text. Of course, still expect photos and, in the future, graphs and educational material.

2.Develop and build an aircraft that would use a mix of rockets and jets, and finding a way to make breaking the sound barrier somewhat easier;

3.Once all that was done, design a jet aircraft capable of breaking Mach 1 at various altitudes, capable of sustained flight at supersonic speeds, and capable of reaching altitudes above 14km.

The first step, while seemingly very simple, would prove to be somewhat challenging in its own right. In fact, the building techniques developed during this phase would prove fundamental for the entirety of the program.

The aircraft that was to be designed had to follow these basic principles: be capable of reaching 10km or more altitude, have two engines in case one failed, and having just one crewmember. The design process started in August 1951 and was over by December, with the first aircraft due to be airworthy by March 1952.

The results of this design phase were finally unveiled in February 1952: the first IRS-XA1 “Phantom” had just been completed and shipped to Cape Canaveral, and a presentation conference took place on the same day, during which the goals of Project Thunder were also revealed.

Blueprint of the "Phantom". Original scan from the time, very low quality unfortunately.

The Phantom weighed just above 3 tons empty, rising to about 5700kg when fully loaded with jet fuel. It was powered by two Derwent V engines, providing a theoretical maximum thrust of 32.20kN total. These engines had originally been developed to powered the Meteor jet fighter in 1945, and while somewhat old, they were also readily available and quite reliable by this point.

The airframe was designed to be capable of supporting 11g maneuvers for at least two seconds, which could very likely result in the pilot passing out. The cockpit was conceived to provide the greatest amount of essential information to the pilot, while at the same time being simple to learn and comfortable to use.

Two Phantoms were built. The first aircraft had its rear landing gear placed slightly more forward than the second one, but that was changed for reasons that I will explain later in the chapter. There also was a primary selection program for the pilots; in the end, only two were selected: Commander Isaac Perry of the RAF, and Captain Joe Mitchell of the USAF (note that these are IRS ranks, and therefore a Commander is of a higher rank than a Captain).

The first flight of the Phantom took place on March 9, 1952, with Cmdr. Perry at the controls. It was a mild morning, with little to no overcast, a perfect day to fly, as Perry himself remarked.

Image 19520309A, Phantom just before take off, photo courtesy of USAF.

Take off occurred at 11:47 AM local time. The plane was in the air after a take off run of around 350m, at a speed of just above 119 knots. It was followed by a F-86 Sabre of the USAF, which took photos of the test flight.

The plane behaved very well, reaching 4500m after around 4 minutes. Some acrobatic testing took place at that height, but after 10 minutes, Perry was ordered to climb and reach 10300m altitude.

Image 19520309B, Phantom flying at around 700m altitude, as seen by F-86 chase plane, photo courtesy of USAF.

At 10300m altitude the Derwents only provided just enough power to keep the aircraft in flight, and airspeed was somewhat lower than at lower altitudes. Moreover, the wings could not provide enough lift to allow for Perry to conduct the high-g maneuvers, and he was allowed to return to around 5500m.

At that altitude the aircraft had incredible performance, being “stable and responsive to inputs”. Perry stayed at that elevation, performing the required tests for twenty minutes or so. After a total forty minutes of flight, he was ordered back to base.

Image 19520309C, Phantom approaching runway to land, F-86 came very close for this shot, photo courtesy of USAF.

Perry slowly approached the runway at Cape Canaveral, due to him not being familiar enough with the aircraft’s performance at slow speeds. He extended the flaps and lowered the landing gear at the designated safe speeds, and started dumping speed by banking left and right in sequence. He touched down at 110 knots.

Image 19520309D, Phantom approaching runway as seen by observers on the ground, photo courtesy of USAF.

Unfortunately, the landing gear failed to support the newly distributed weight of the plane, whose tail slammed into the concrete and was dragged along the runway until the aircraft came to a stop. Perry was, however, uninjured. The cause of this failure was due to the landing gear being too far forward. This was rectified in the second airframe designed, and the first one was fixed and used again in the future as a training airplane with a second seat added.

There was a second flight of the Phantom on April 16 of the same year, but unfortunately no photos remain of it. This time Captain Mitchell was the pilot, flying the second Phantom with the rectified landing gear. The flight went perfectly, and Mitchell noted the same things about the aircraft that Perry did, despite the different arrangement of the landing gear: the aircraft was very stable and responsive, but did not fare that well above 9000m. Later flights were not registered on the IRS Manifest.

While the Phantom was not a groundbreaking aircraft, its development proved essential for two reasons: the materials and structure used to build it were later put to use in almost every aircraft of the 1950s, and it was a very good candidate for a training airplane. Indeed, when the IRS later required Flight Engineers and Specialists not yet qualified for jet duty, the Phantom would be used to teach the candidates the basics: its utility was extended well beyond what had been projected, being used as a basic jet trainer well into 1962, with upgraded engines and instrumentation.

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Aerobee launches would resume in June, after a series of upgrades to the facilities at Cape Canaveral, which streamlined assembly, reducing costs and the time between launches.

Aerobee-5 was launched on June 15th, 1952. It carried a scientific payload aimed at studying the properties of the thermosphere around 200km in altitude. The mission was a success with all objectives achieved.

Aerobee-6, launched on June 25th, 1952, was the proof that the IRS was becoming recognized at an international level. The payload, designed by James Van Allen of the University of Iowa, was just at the top of the Aerobee’s capabilities. It was made of a series of Geiger-Muller counters which would detect any radiation present in space. The almost over encumbered rocket reached around 176km altitudes, and the results it obtained were interesting and necessitated further investigation.

The Aerobee program had been a resounding success for the IRS, but unfortunately these sounding rockets were limited to (relatively) low altitudes. A new, upgraded version of the Aerobee was in the works by mid-1952, but a stopgap measure was needed in the meantime.

The IRS still possessed a small number of A4 missiles that were ready to use, but these were limited to even lower altitudes than the Aerobees. The IRS engineers had always wondered however whether or not a rocket motor could be ignited in flight. This was the perfect opportunity to test the concept.

Aerobee-A4 schematic.

A design reminiscent of the Bumper sounding rocket, the A4-Aerobee was a simple and cost-effective project.

The booster stage was an A4 ballistic missile with its tip removed to accommodate an SD-36 decoupler, the same used to separate the Aerobee from its solid booster motor. This part of the flight was very similar to that of a simple A4. The rocket engine would ignite two seconds before liftoff, and then would burn for 66.5s bringing the rocket to an altitude of around 25-30km. As the engine ignited, a timer was started. Fifteen seconds before booster cutoff (T+51) the rocket started rolling to spin stabilize the Aerobee upper stage, and two seconds before booster cutoff (T+64) a signal was sent to a spark plug positioned below the XASR-1 engine on the Aerobee, and the Aerobee itself so that the upper stage engine would ignite.

The Aerobee stage then separated at T+67 and continued burning for another 65 seconds. The rocket would then coast to apogee, which was projected to be in excess of 800km.

Image 19521002A, the first Aerobee-A4 rocket, here pictured a few hours before launch.

The first flight of a series of three took place on October 2nd, 1952. Aerobee-7 was a test flight and as such carried little to none scientific payload: effectively nothing more than a simple thermometer and barometer. There was a failure in the A4 guidance about halfway through the burn: the rocket started tumbling slightly, and despite the spin stabilization, the Aerobee started veering off-course. Nonetheless, an impressive altitude of 754km was reached.

Aerobee-8 occurred almost two months later, on November 27th. The stability problems, traced back to an exposed wire that short-circuited, were solved, and the flight went perfectly: the rocket reached an even more impressive altitude of 839km.

Aerobee-9 took place another two months later, on January 30th, 1953, and would be the last flight of the first generation of IRS Aerobees. The sustainer stage reached an altitude of 800km before the termination command was issued.

Between Aerobee-6 and -7, however, another launch took place. It was the most ambitious mission yet undertaken by the IRS: the recovery of a biological sample from space.

Schematic of the A4 BSR, showing the rocket assembled and the payload module.

The A4 Biological Sample Return (BSR for short), was a major overhaul of an A4 ballistic missile.

The lower part of the rocket (up to the Liquid Oxygen tank) was identical to that of a standard A4, with all modifications happening from the Ethanol tank upwards. The conical tank structure of the original design had been replaced by a simpler, shorter cylindrical one, which contained the alcohol fuel required to run the rocket motor. On top of this structure was an aerodynamic fairing, made out of steel, which was custom built to fit the very special payload. Overall, the rocket was lighter (yet sturdier, but carrying the exact same amount of fuel, which allowed for slightly higher delta V, and therefore altitude reachable.

The payload was the most interesting part of this rocket, making up almost 40% of the total cost of the mission. It was made of, from top to bottom (refer to blueprint for visualization):

1.A CU-47WS-B telemetry module, adapted from the Aerobee one, which collected the altitude and velocity data after the payload separated and relayed it to the ground units. It also had the function of engaging the parachutes once pressure and speed were deemed sufficient.

2.The Biological Sample Capsule itself, carrying a variety of animals ranging from fruit flies to mice, and some plants as well. It was hoped its occupants would return home safely.

3.The parachute recovery module, which was made of two separate parachutes – a drogue one which deployed below 30km altitude and fully inflating around 2500m, and a main chute which opened at 900m altitude, just after the drogue chute was cut, and fully inflated by 700m altitude.

4.A high-quality film camera, which was supposed to take high resolution images after the payload separated from the rocket.

5.Three drag aerodynamic fins installed around the camera module, which had two functions: stabilize the payload as it descended whilst slowing it down enough for the parachute to safely deploy. They also contained a series of inflatable floats in case of a water landing.

6.Two sensor modules, a thermometer and a barometer, which sent data to the telemetry unit so that it could deploy the parachutes safely.

The mission, named A4-2, took place on August 28th, 1952. The rocket performed as expected, recording a maximum acceleration of around 9.04gs just as the fuel ended, which was deemed acceptable by the research teams. The rocket then coasted to 110km altitude, at which point the fairings were discarded and the payload separated from the missile. It then reached a maximum apogee of 218km, before returning back to Earth. The descent phase recorded a peak-g force of around 11.5gs, which was higher than planned. Nonetheless, the drogue chutes deployed successfully at 25800m, and the payload landed safely 5 minutes later, in the sea, about 1.5km offshore from the Cape.

The data recovered from this mission was incredible, and would later prove fundamental for the success of the IRS’s manned spaceflight program. Nonetheless, the high costs and low availability of the A4 missile would make this A4 BSR flight one-of-a-kind. The IRS kept sending biological samples to space on US-built sounding rockets, however, no mission carried such a heavy, and advanced, payload.

@MatterBeam, thine request has been answered with approval. Rejoice, you humans!

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Despite the apparent inactivity at the IRS’s Aeronautics Department, work indeed continued on developing advanced aircraft. A series of conferences took place at the IRS Headquarters in Florida during 1952, where new building techniques were discussed.

In reality, the most important point to come out of the meetings was a revolutionary discovery about transonic aerodynamics. Richard T. Whitcomb, a researcher at the National Advisory Committee for Aeronautics (NACA), had independently discovered the so called “area rule”, which would revolutionize aircraft design as a whole. Whitcomb realized that the shaping of the aircraft fuselage had to keep in mind the overall surface area of the aircraft, therefore, the fuselage should actually be narrowed where wings were present.

The IRS soon started working on the concept, as did others, and by late 1952 they had come up with a mock-up of a test vehicle based completely around the concept of an area rule, perhaps exaggerating the required narrowing. The aircraft was powered by two J85 turbojet engines, had swept wings, and was very unique due to the extreme narrowing of the fuselage. A series of aerodynamic tests, however, found out that the aircraft would not be able of breaking the sound barrier in level flight, albeit being quite near, reaching a projected speed of Mach 0.92 at around 10000m altitude.

A redesign was due. In place of completely modifying the fuselage structure, which would require much time and money, a more “brute-force” approach was taken. Why design the perfect aircraft, when you can simply add more thrust by other means? Thus was born the IRS-XA2 Daemon.

Daemon schematic

The Daemon, unable to break the sound barrier on jet power alone, was fitted with an XLR11 rocket engine of Bell X-1 descent, powered by a mix of alcohol and liquid oxygen, and capable of shutting down separately each of its four combustion chambers, which effectively meant that the rocket could be throttled down to 25% of its maximum thrust. The XLR11 would not ignite on the runway, instead the aircraft would first reach 10000m altitude and then fire the rocket, which would then burn for 1 minute and 29 seconds.

The XA2 had an extremely narrowed fuselage in the middle of the aircraft, which later tests showed it was indeed excessive, and subsequent designs would be much gentler in their following of the area rule. The cockpit had been reused from the Phantom, with some adjustments such as the addition of the rocket ignition button, so that the pilots would already know their way around.

The aircraft’s main powerplant were still the two J85-GE-4 turbojets, providing the required thrust for the majority of the flight, and were also used in conjunction with the XLR11 to boost its maximum speed further up. Due to the low mass of the Daemon, in this flight configuration, it had a substantial acceleration which would bring it up to projected speeds of much more than Mach 1.

The first, and only, flight of the Daemon took place on February 21st, 1953. The pilot was selected to be Commander Isaac Perry, who had also flown (and crashed, one might say) the first Phantom aircraft.

Image 19530221A, the Daemon just before launch, photo courtesy of USAF.

Perry took off early in the morning, around 10AM, in a slightly cloudy day, shadowed by two F-86 chase planes of the USAF. The Daemon took off somewhat slowly due to the dead weight of the rocket engine and its propellant. To make up for it, the aircraft had a smaller supply of kerosene, which limited its time in the air to approximately 40 minutes at most.

Image 19530221B, the Daemon has taken off and is climbing as seen by F-86 chase plane, photo courtesy of USAF.

Image 19530221C, Florida as seen from the cockpit of the Daemon, photo taken by Cmdr Isaac Perry.

As the aircraft accelerated, Perry reported that it was becoming progressively easier to fly, and by around 600km/h, it was “very enjoyable, it just looks dreadful”.

Perry kept climbing until he reached the designed altitude of 10km, at which point he put the jets on full thrust and accelerated up to the aircraft’s maximum speed of Mach 0.88, with the F-86 lagging slightly behind it.

About two minutes later, Perry raised the safety cover on the ignition button, and after a somewhat dramatic pause, he pressed it. The XLR11 rocket engine started with a loud roar, and Perry was slammed back into his seat by the sudden acceleration.

Image 19530221D, the Daemon has reached maximum speed on jets and Perry readies to ignite the rocket, photo courtesy of USAF.

As soon as the rocket motor ignited, the F-86 pilot reported that he would not be able to keep up with Perry, but that he’d still try his best. After just forty seconds the Daemon looked just like a dot in the sky, it now flying at an altitude of 11km.

Image 19530221F, the Daemon is that bright dot near the centre of the image, photo courtesy of USAF.

When the XLR11 finally ran out of fuel, Perry had reached a speed of around Mach 1.47. When he slowed down under the speed of sound he started to turn back, and he rendezvoused with the F-86. As they then descended to land, Perry went full throttle again and broke the sound barrier in the very slight dive he was into.

Image 19530221G, Perry approaches the runway for landing, Cape Canaveral AFB can be seen in the upper right corner, photo courtesy of USAF.

Perry touched down a few minutes later, with just five minutes of fuel remaining. He was soon reached by the ground crew, who checked the aircraft and took photos of it. Perry had become the first IRS pilot to fly at speeds exceeding the sound barrier.

Image 19530221H, the Daemon has landed at Cape Canaveral AFB, as seen from the perspective of the ground crew, photo courtesy of USAF.

The Daemon was certainly an improvement over the Phantom, but it was flawed in its own ways. The danger of the rocket engine and its propellant were also part of the reason why it never flew again, being kept in storage indefinitely.

Nonetheless, it was a pioneering aircraft, and understanding its flaws and strong points would prove to be fundamental for the next step of Project Thunder. Indeed, it was finally time to reliably break the sound barrier, with no rocket engines involved!

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I searched all over the web for some old rocket schematics, but in the end I settled with the design from a V2 drawing. I then made some adjustments to fit my OCDs (I’m an aerospace engineering student, I have many of them). Actually it’s not that hard to make the blueprints in Photoshop if you know your way around a couple of effects. It’s just tedious if you need to check the specifics of what you’re drawing every two seconds, since the combo KSP + Photoshop tends to eat my RAM alive.

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Actually it’s not that hard to make the blueprints in Photoshop if you know your way around a couple of effects﻿.

I don't suppose you would share your secrets? Looks kinda like using the "find edges" option in Photoshop with Kronal Vessel Viewer screenshots, but it is a lot cleaner than I have been able to get with my attempts.

Anyway great stuff, I'm a big fan of the "real world artifact" theme you have been using for the pics.

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To celebrate the start of my 5th year on these Forums, and 1000 views on this thread, I proudly present you

VII: The Starry Sky Above, Part 5

Higher Than Ever Before

While everyone at home was focused on the success of the Daemon experimental aircraft, the IRS rocketry team was ready to unveil the next, and much improved, version of the Aerobee, approved for production in February 1952.

Aerobee II schematic.

The Aerobee II, as it was commonly called, was much bigger than previous iterations, while maintaining the same 30cm tank diameter; this was possible due to lighter construction techniques.

While the booster stage was identical to that of the Aerobee I (refer to Chapter III for more details), the sustainer had been thoroughly updated. The engine was now an Aerojet AJ10-27 (which would become much more important later on), which improved upon the XASR-1: it was much more powerful, with around 70% more thrust, at the cost of slightly worse specific impulse, however, this was offset by the longer burn time of the combustion chamber. The telemetry transponder had also been updated from the Model 3987 to the Model 4000, which was more capable and weighed less. The payload section and parachute instead were identical to those of the Aerobee I, with the only difference being that the payload section was now modular, with cylindrical modules attachable underneath the nose cone when needed. When the payload section was stretched the rocket was referred to as the Aerobee-IIs, although it was never a formal designation.

There was a single launch before a one-year launch hiatus. Aerobee-10 launched on May 11th 1953, and was a success. The rocket reached a maximum apogee of 321km, and kept transmitting data until shortly before impact, since the parachute had been removed due to issues in the arming mechanism. Nonetheless, this launch proved that the new version of the Aerobee was capable of reaching nearly 100km more than the previous iteration.

After this launch there was silence for quite some time at the IRS test site in Florida. This was due to a series of negotiations between the Society and the US Army’s ABMA, which led to an agreement which spawned the Deacon family of rockets.

Deacon I schematic. The LOX and Ethanol tanks are inverted, I was likely very tired.

The Deacon A-6, or Deacon I, was a derivative of the ABMA’s own PGM-11 Redstone ballistic missile, although nearly 70% of the rocket was of a completely new design.

It had a maximum diameter of 1.8m (excluding fins) ad it was powered by the same engine as the Redstone, the North American Aviation NAA-75-110 A-6, which in turn had been derived from the A-4 engine of WW2 heritage. As its progenitor, it had no gimbal capability, with all attitude control being provided by four thrust vane fins during the burn phase. As the rocket burnt all of its propellant, and exited the atmosphere, it then switched to an innovative attitude control system, which vented excess nitrogen through four thrust vanes, providing for pitch and yaw, but not roll, control. The Deacon A-6 rocket was the most powerful missile ever tested by the IRS until then, having more liftoff thrust than even the A-4.

It made four flights from early 1954 to early 1955, before being retired for reasons that will become important later on.

The first flight, A-6 0T, was a test flight, as such, per IRS tradition, it carried no payload to allow for the maximum altitude to be reached. It occurred on March 25th 1954.

Image 19540325A, launch of the first Deacon I, visible is the cloud of dust raised by the engine exhaust.

The rocket at take off raised a lot of dust, and the observers on the ground, which included a number of top officials from both the USA and the UK, were not able to see much of the flight until the dust settled. Nonetheless a few photos were taken, including the above.

The flight was a success, with the engine burning smoothly for the whole 2 minutes and 24 seconds of propellant available. The rocket reached a reported altitude of 419km, and the results obtained from the received telemetry demonstrated that it could actually support even higher stresses than previously thought. The missile was not equipped with a recovery system and was destroyed on impact with the ocean, as all successful Deacon flights.

A-6 1, launched on September 6th 1954,was intended to be the second flight of the Deacon, but a feedline failure just before launch meant that the engine had a hard start and nearly exploded: although the rocket was mostly intact, it would not fly again.

A-6 1A was the second attempt at launching the A-6 1 payload. The launch occurred on October 20th 1954, and this time was a success: the rocket reached an altitude of 210km before crashing in the Atlantic Ocean.

A-6 2 would be the fourth and last flight of a single stage Deacon I. This flight will be discussed at the end of this chapter.

The first Deacon I flight had demonstrated the capability of the stage to sustain very high stresses. The engineers then thought of a way to exploit this quirk. The result was as simple as it was genius: why not strap on top of a Deacon a whole Aerobee II stack, complete with the solid motor?

Aerobee-Deacon I schematic.

The Aerobee-Deacon I was indeed just that: an Aerobee acting as an upper stage for the Deacon lower stage.

The flight profile was similar to that of the older Aerobee-A4: the Deacon acted as a booster stage, burning for 2 minutes 24 seconds and carrying the stack up to 30km altitude; ten seconds before burnout the rocket entered a spin to stabilize the upper stage.

Then the Aerobee separated and both the 2.5K solid and the AJ10 ignited, when the solid motor was depleted the sustainer finally separated and kept burning until it either burned all of the propellant, or it exploded.

Image 19540626A, Aerobee-11 on launchpad, a few hours before launch.

The first flight of such a design, Aerobee-11, occurred on June 26th 1954. It was a resounding success. The Aerobee stack, carrying a somewhat advanced camera, reached a final altitude of 1740km, which beat every record then standing, while taking a breathtaking photograph in the meanwhile; this photo would make front page on many newspapers.

Image 19540626A, Earth as seen from 1740km altitude, the Yucatan peninsula can be seen in the middle, follow the coast from the right to more easily spot it.

After Aerobee-11, two further flights were made using Aerobee II rockets, Aerobee-12 and Aerobee-13, the first being a success and the second being a partial success due to a problem in the arming mechanism for the chute meaning it made an hard landing in the ocean.

The following four flights Aerobee-14 to Aerobee-17, often occurring months from each other, were all Aerobee-Deacon I flights. They were all successful and all reached altitudes in excess of 1000km, depending on the payload and mission requirements.

It’s time to return to that final Deacon I flight, A-6 2, taking place on January 24th 1955. It was a pretty standard flight by itself, reaching and altitude of 210km before crashing in the ocean as usual. But that didn’t explain the huge crowd of journalists and VIPs attending the launch. What would change the course of history, was what happened after the flight.

A public conference was called just after lunch time, outside of the hangars at Cape Canaveral. It was broadcast by TV and radio all over the US, and in some cases even Europe. Sir Philip Perrington and General Garret Woodward, who had been reelected as heads of the IRS just a few months earlier, appeared over the quickly-built stage.

Their words were a shot that would be heard around the world, and would forever alter the course of history. As a contribution to the International Geophysical Year of 1957, the US and the UK, working together under the banner of the IRS, would launch a satellite into orbit by the end of January 1957.

These words echoed for a long time after they were first spoken. Just four days later, on January 28th, the Soviet Union announced plans to also launch a satellite into orbit by January 1957. Something new was happening: a “race to space” was just starting.

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A year had passed since the first Daemon took to the sky in February 1953. It had been one busy year for the aeronautics department at the IRS. Many inventions and discoveries had changed the way aircraft were being designed and built.

The International Rocket Society took advantage of their lead in this sector of the engineering science. By October 1953 the first prototype of a revolutionary aircraft was flying on its own power. The engine it sported wasn’t powerful enough to propel it past Mach 1 yet, and the aircraft itself would end up being slightly smaller and significantly lighter than later instances of the plane. In January 1954 the second prototype of this airplane was flying. It was identical in everything but the engine to the eventual production version. Finally, in April 1954, the IRS-XA-3 “Thunder” was ready for action.

Thunder schematic.

The XA-3 was the product the IRS had always hoped to achieve with the appositely named Project Thunder. It was a heavy aircraft at 14412kg while loaded, weighing as much as a B-25 bomber from WW2. This didn’t affect performance, however: the Thunder would prove to be both nimble and extremely fast.

The engine issues that had prevented the prototypes from breaking the sound barrier had been solved when Pratt&Whitney agreed to provide some J57-P-21 engines for use aboard the Thunder. These engines had two modes of operation, a “dry” one and a “wet” one, the latter, also known as “afterburning” mode, considerably increasing thrust at the expense of fuel efficiency. This wasn’t a problem however: the XA-3 wasn’t meant to achieve a combat range of sorts, its only purpose being scientific. This version of the J57 was capable of outputting a maximum of 45.4 kN of thrust when in dry mode, and 75.4 kN when at full afterburner. The maximum range of the aircraft, when flying at cruise speed, was of around 2650km.

The Thunder also had a new cockpit design, allowing for a pilot and a scientific officer to fly together, thus maximizing scientific potential due to pilot workload being decreased. The aircraft was also equipped with two airbrakes to help slow down due to the absence of flaps (this was due to the delta wing design). The airframe followed the area rule as closely as possible and much better than the Daemon, but the high wing loading meant for high speed landing, which required a drag chute to efficiently slow down the vessel. The design was very similar to that of the Convair F-102, although they were conceived completely independently and it was a mere coincidence that they resembled each other so much.

The first flight of a production Thunder occurred on April 3rd 1954, with Captain Joe Mitchell as pilot and Senior Engineer Douglas Cherry in the rear seat, monitoring the aircraft’s performance. No chase plane had been assigned to the flight, but Cherry carried a camera on board with him.

Mitchell slowly increased thrust, eventually reaching the full power output of the J57 engine. The acceleration was immense, the two crewmembers being slammed into their seats the whole time. Takeoff occurred at high speeds due to the high wing loading of the Thunder, but as soon as the aircraft was flying Mitchell and Cherry noted the very good handling of the aircraft. After a couple of minutes flying at low speeds and altitudes, the pilot once again throttled to maximum power and raised the nose to reach a higher altitude.

They eventually reached an altitude of 10500m, at which point Mitchell stabilized the vehicle but keeping full throttle hoping to break Mach 1. Just a few moments later, him and Cherry heard a loud bang: they had broken the sound barrier on jet power alone.

As they reached around Mach 1.27, Cherry advised Mitchell of not accelerating further as the engine was reaching its maximum operating temperature, which was really weird since the J57 was rated for a higher maximum temperature. Mitchell nevertheless complied, not going any faster, but still keeping the aircraft flying at that speed for about 10 minutes.

Image 19540403B, photograph of the Atlantic Ocean taken by SEng Douglas Cherry in flight at 10500m altitude.

After that time had elapsed, Mitchell started turning around while still at supersonic speeds, slowing down to subsonic in the process. The two were back at the Cape half an hour later, with the tank half empty.

The test had been a huge success for the IRS. Most of the primary goals of Project Thunder had been achieved, although there was still room for improvements. The team worked hard over the course of the following year, and in the end they managed to solve the engine temperature issues, as well as updating the cockpit layout after some feedback from Mitchell and Cherry.

The second test flight of the XA-3, this time its definitive version, occurred on February 27th 1955, with Commander Isaac Perry and Specialist First Class Danny Higgins at the controls. This time two F-100 Super Sabre of the USAF had been assigned as chase planes for the mission.

The series of tests that were to be conducted were meant to push both man and machines to their limits. Climb rate, maximum speed, high velocity turns, acrobatic maneuvers and dive tests were all planned among others.

The aircraft took off in the early afternoon. Perry brought the aircraft over the sea in case something went wrong, at which point he engaged the afterburner and started an extremely steep climb that changed the vessels’ altitude by 1500m, before suddenly rolling over and diving steeply, eventually leveling at around 200m altitude, briefly going supersonic in the process.

At this point, Perry descended to 50m altitude while throttling down to bring the aircraft to Mach 0.8. After waiting for the chase planes to position themselves, he again went full throttle and climbed at the maximum angle that didn’t make him lose speed.

The aircraft eventually rose to 11km altitude. The results of the test were recorded: the Thunder reached 1000m in 21 seconds, 3000m in 69 seconds, and 10000m in 219 seconds, impressive times indeed.

Image 19550227D, Thunder at an altitude of 11000m, engaging afterburner to set speed record, photo courtesy of USAF.

At 11km altitude, Perry kept the full throttle, and by doing so the aircraft reached a maximum speed of 1879km/h, or around Mach 1.728 at that altitude. The Thunder was officially the fastest aircraft ever built, and would hold the record until late 1957, when it was surpassed by a USAF F-101.

Image 19550227E, clouds over the East Coast as seen from 11km altitude, photo taken by SpFC Danny Higgins.

After some time at Mach 1.7, Perry slowed down to just above Mach 1.25, turned around and entered a 20° dive at maximum dry thrust, reaching 1980km/h and requiring use of the airbrakes to slow down quickly enough, at 1600m altitude.

Image 19550227F, Thunder emerging from the clouds after diving from 11km, photo courtesy of USAF.

Perry then brought the aircraft back up, this time to 7000m, just above the clouds. At this altitude, and thanks to the decreased fuel load due to the extensive use of the afterburner, the aircraft was just capable of something called “supercruise”, effectively flying supersonic without the use of afterburners or rockets.

The two Thunder flights were a remarkable success for the IRS, its Project Thunder having met or even surpassed all of its objectives. The discoveries made by the aeronautics department had truly changed the way flying was conceived almost overnight, one could say.

The team was unfortunately unable to capitalize on its successes, due to the focus of the IRS suddenly switching to Project Orbiter, its announcement having been made just a month before the second XA-3 flight. Nevertheless, most of the department went on to work with the rocketry department to design the advanced orbital rocket required for Project Orbiter. Just a small team of engineers was now left working on aircrafts, and, at least for the time being, they could only dream.

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The announcement of Project Orbiter on January 24 1955 had called for a major design competition to select a launch vehicle capable of putting a satellite in orbit. The specifications for such vehicle were set on February 16: they called for a payload capability of around 30-100kg to low Earth orbit (LEO), and the payload itself had to carry at least a radio transmitter capable of transmitting for three months.

The design competition would see not only the IRS’s own teams of engineers participating, but also several private and public companies, both American and British. Still, the commission preferred for an internal design to then assign to a series of companies to build. Indeed, the invention of new tank technologies at the IRS R&D department, in conjunction with the ABMA, would make internal designs much better suited for a launch vehicle than any external one.

In the end, the IRS settled for an upgraded version of the Deacon as the lower stage, a second stage that was yet to be determined, and a solid rocket motor acting as kick stage to put the satellite into orbit. A second design phase started. The teams of engineers at the IRS, after a long study phase, proposed two designs, the first with an American-made second stage, and the other with a British-made one; they were named Alcor and Gamma, respectively. They were presented to the commission on September 28 1955.

Gamma launch vehicle proposal schematic.

The two rockets were identical in all but the second and third stages. The lower stage was a Deacon II, a larger Deacon I with an uprated NAA-75-110 A-7 as its engine, rated for 416.2kN thrust, not burning the Ethanol-LOx mixture of the earlier A-7, instead using Hydyne, a hypergolic propellant, as fuel, while retaining the Liquid Oxygen oxidizer. This meant higher thrust and specific impulse compared to the previous mixture. The stage had a burn time of 159 seconds, which was a little over the rated burn time of the A-7, but that was a matter of little concern due to the reliability of these motors, at least under the IRS.

The Gamma second stage made use of the Gamma-2 rocket engine (hence the name), with a thrust of 68.23kN. This engine was being developed by Bristol-Siddeley in Britain, and it was a most unusual design. Instead of the usual Kerosene-LOx (or Ethanol-LOx, for that matter) mixture used in many rocket designs, it burned Kerosene and HTP, with a catalyst to decompose the peroxide, the resulting mixture being completely hypergolic. The stage burned for 140 seconds.

The Alcor second stage, instead, mounted a single AJ10-37 engine produced by Aerojet, producing 33.8kN of thrust. This rocket motor was a derivative of the engines used on the Aerobee family of rockets. It used a more conventional hypergolic mixture of UDMH and IWNA, which was nonetheless extremely toxic and required special equipment to be handled. The stage burned for 115 seconds, and was narrower in diameter when compared to the Gamma stage, 0.9m versus 1.2m diameter.

The third stage was to be either an Aerojet X-242 solid rocket motor burning PSPC, or a cluster of three Thiokol Baby Sergeants burning a mixture named T17-E2, depending on payload weight, with the former motor being the most powerful alternative. The Gamma rocket, instead, carried no third stage.

The Gamma launch vehicle was the least powerful of the two, but also the cheaper alternative. It could carry around 50kg to orbit, which was within the parameters set by the IRS for its payloads. It would also be available much sooner than the Alcor, making a launch possible by mid-1956, if everything went well. The Alcor, on the other hand, was much more powerful, being capable of carrying 75kg to orbit in its Baby Sergeant version, and a whopping 150kg to orbit in its X-242 configuration. The AJ10 also had much better development perspectives compared to the Gamma. The downside to all this were however a higher development and construction cost for the vehicle, and, most importantly, it would be available for flight later compared to the Gamma, being expected for a launch to orbit by January 1957. Considering that the Soviets were planning to launch a satellite as well, every day of delay could mean that the IRS wouldn’t be the first to achieve orbit around the Earth.

In the end, in December 1955 the IRS committee selected the Alcor as the launch vehicle that the Society would use to launch its early satellites into orbit, citing the higher payload capability and better development future among other reasons. All work soon shifted to that one launch vehicle.

Alcor launch vehicle schematic.

Test flights of the earlier Deacon II had had aerodynamic issues due to the stubby wingtips. To address this issue, the final version of the stage had much larger wingtips.

The first full stack test of an Alcor rocket took place on March 6, 1956. It carried a dummy payload weighing 341kg, way above the maximum payload capability for the launch vehicle. This was done to ensure that the payload wouldn’t be accidentally put into orbit. It would take some time before the first “real” payload would be ready for action. The test flight, at this point simply named TV-1 (TV standing for Test Vehicle), went perfectly. A series of photographs were taken, and, recently, a simulation of the flight has been rendered.

The rocket kept climbing, the pale blue-purple exhaust slowly expanding as the air pressure decreased. The vehicle reached max Q (maximum dynamic pressure) at 17500 meters altitude, and the shockwave around its body was well visible from the ground.

SIMULATION. The Alcor launch vehicle passes through Max Q.

The first stage shutdown as expected after burning for 2 minutes 39 seconds at 55000 meters altitude. The rocket coasted for 10 seconds to an altitude of 75km before the two stages separated.

SIMULATION. The Deacon II first stage has run out of propellant and the booster is coasting.

SIMULATION. The Alcor stage separates from the Deacon II, while the ACS struggles to keep it on course.

After stage separation, the attitude control system thrusters started burning to stabilize the propellant in the tanks before the main engine ignited, and to control the attitude of the stage. This lasted for three seconds, after which time the AJ10 ignited and the ACS went into roll control mode.

SIMULATION. The AJ10-37 of the Alcor stage ignites. Note the hypergolic, overexpanded, plume.

At 110km altitude the fairings were separated as they were now unnecessary.

SIMULATION. Fairing separation occurs smoothly.

After a burn of 1 minute 55 seconds the engine shutdown as planned. The attitude control system was fully activated again to stabilize the rocket.

SIMULATION. SECO has happened and the Alcor is coasting to apogee.

After a coast of nearly three minutes, as the booster was forty seconds from apogee, the ACS started the spin-up process. Ten seconds later the stage was spinning at a steady 45rpm, which made sure the third stage would be spin-stabilized as it had no attitude control of its own.

SIMULATION. The ACS engages to spin the rocket to 45 rpm.

Twenty-two seconds before apogee the rocket staged again, and the X-242 third stage ignited. The burn lasted for around 45 seconds, slightly after apogee. After the burn was concluded the payload separated from the booster. Had it been lighter it would have reached orbit, instead this time it was left on a ballistic trajectory to be destroyed by the rigors of atmospheric re-entry.

SIMULATION. The X-242 solid rocket is ignited and burns for the full duration.

SIMULATION. The dummy payload has separated from the X-242. It will burn up above Africa.

The second test flight, TV-2, occurred a month later on April 13 1956. The launch was considered a failure due to the second stage hard-starting, but not exploding. This meant that the rocket not only reached a lower altitude than planned, it also didn’t achieve the planned velocity. Unfortunately, no images survive of the flight, and no simulations of it have been rendered. The only remaining image of this flight is a graph extrapolated from the telemetry readings.

Graph of TV-2 telemetry, restored and ehnanced. Originally each function was on its own display, here they are merged for ease of reading.

Nonetheless, the test flights were considered an overall success for the IRS. The AJ10 needed some further testing to increase its reliability, but the rest of the rocket was thought to be flight-ready. The avionics had been working perfectly, and the A-7 was by then a well-known design. Although a TV-3 had been planned for mid-August, it was scrapped in favor of a proper orbital flight, due to the increasing fears the Soviet may launch a satellite into orbit before the IRS could.

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This is turning out to be really good. Supercruising already! Maybe try attacking some payloads to that plane?

The fun thing is that I didn't intend the plane to supercruise, but when I was flying it back to the KSC I noticed it was going supersonic even on 25% afterburner, so I just set the thrust to the maximum dry power, and it went supersonic, albeit barely. It was the combination of high(ish) altitude, low weight due to fuel usage, extremely good TWR (from 0.53 fully fueled to 0.83 completely empty), and of course the efficiency of the delta-wing design. I was very surprised too when it happened.

Regarding the payloads, I have flown a series of "pods" around the Americas off-screen, and one time I attached an Aerobee to one of its wings for the lols . That would make for a good mission to show, especially now that I'm unlocking the more advanced Aerobees.

On 4/6/2019 at 4:23 PM, MatterBeam said:

Also, how did you collect and display telemetry from the TV-2 launch?

That is the MechJeb Flight Recorder, I took a screenshot when I had the window opened and then polished everything in Photoshop, before creating a simpler and more direct interface for ease of comprehension.

By the way, this is not dead, I simply had little time to spare for KSP, and I'm working on the next chapter. And the next chapter will be quite an important one. You can guess what it is... because I literally wrote it at the end of the last post .

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While the Alcor launch vehicle was being improved in terms of reliability, especially for the relatively new AJ10-based upper stage, the IRS was collaborating with several universities from both the US and the UK to design and build the scientific experiments that were to be sent into orbit, and a committee was formed to assign a name to the artificial satellite, the program having been officially referred to as “Project Orbiter” up until then.

The satellite design and the experiments it would carry were finalized on June 29 1956, and a name was chosen by August 2. The artificial moon would be called “Ethereal 1”, with the Ethereal name being retro-fitted to the two test launches, which therefore became Ethereal TV-1 and Ethereal TV-2.

Drawing of the Ethereal 1 satellite showing the major components and experiment arrangement. This was intended for the general public.

The Ethereal 1 satellite was a 28kg probe made of two main components: the experiment section and the telemetry and communication section. The low weight of the satellite meant that the Alcor rocket that would send it into orbit would use three Baby Sergeants as the third stage in place of the usual X-248.

The experiment section was the elongated blueish/white-striped part at the top, the blueish color coming from the stainless-steel alloy used in the construction. It contained the main circuits that operated the probe, and, obviously, the experiments. To avoid launching an overly complicated, and therefore heavy satellite, the scientific potential of Ethereal 1 was limited to just four experiments, albeit very important, and certainly interesting, ones. Apart from the standard temperature and pressure sensors suite of Aerobee descendance, it also carried a micrometeorite detector that employed a small microphone to record the impacts on the satellite body, another micrometeorite detector in the form of erosion gauges, and, most importantly, a cosmic-ray detection package based around the Anton 314 Geiger-Müller tube, devised by Dr. James Van Allen and Dr. George Ludwig at the University of Iowa.

The back section, painted white, contained the satellite’s batteries among a series of low-power transmitters and high-power antennas, the latter being mounted on outside of the satellite. Two antennas usually were on at all times, and the other two were spares in case of a malfunction. Each omni-directional antenna had an effective range of around 10Mm, consuming 5 Watts when on and having a maximum data transfer rate of 270kbit/s.

The name Ethereal was chosen after a long debate, in which very good names such as Explorer, or even the simple and direct Orbiter, were discarded. The name came from the classical element of ancient and medieval science, the Aether or Ether, which was regarded to be the material that fills the universe above the terrestrial sphere, i.e. above the Moon in the classical geocentric universe. Although it was argued that the satellite wasn’t meant to travel beyond the Moon, not even getting close to it in reality, it was still a very fitting name for a man-made moon that was supposed to circle around the Earth in the “ether” of space. Ethereal was therefore approved on August 2, and the following day work was started on the launch vehicle and on the satellite, with work expected to be completed by the end of 1956.

However, the scare of a potential Soviet orbital launch meant that a series of time-saving measures were taken, yet not affecting the quality of the final product. These were indeed just efficiency upgrades that streamlined the various production processes. Incredibly, work was completed by October 13 1956, barely two months after it had started. The launch vehicle and payload arrived at Cape Canaveral AFB on October 27, and they were assembled on-site in the following days.

Finally, an announcement was made to the public: the orbital attempt would take place on Saturday, November 3 1956. Depending on weather conditions, the launch would occur either in the morning, or the early afternoon hours.

A great crowd started gathering at the first light of dawn, being redirected by the military staff at Cape Canaveral AFB to a safe location that still allowed for good vision over the launch site. The rocket had already been erected the day before at what would soon be called Launch Complex 1, or LC-1 for short.

A number of journalists were allowed access to the launch pad some hours before launch to take pictures, and of course to report for the live television feeds. Among those present was, as always, Danny Brewer from the CBS.

Image 19561103A, rare color photograph of the Ethereal 1 stack taken just before launch, courtesy of CBS' Danny Brewer.

The journalists had to leave LC-1 at around 11:30 in the morning, due to the final preparations taking place before the launch occurred. The weather was perfect, a sunny day with low winds at altitude.

Finally, at 13:15 the sirens started sounding, and the last crews evacuated the launch pad. Three minutes later, at 13:18, a loud roar was heard at Cape Canaveral AFB: that of a liquid rocket engine igniting. Three seconds later, the rocket had reached full thrust and was released from the clamp. Ethereal 1 had taken off to reach for the stars.

Image 19561103B, another rare color photograph of Ethereal 1 taken just after liftoff, photo courtesy of CBS' Danny Brewer.

Image 19561103C, black and white photograph of Ethereal 1 taken a few seconds after launch, photo courtesy of the BBC.

The take off of such a majestic machine was a sight to behold for everyone at the launch site; many had their mouths gaping in astonishment.

The rocket kept climbing through the lower atmosphere, the plume expanding as altitude increased, and soon everything that could be seen from the ground was a tiny dot in the sky.

After 160 seconds the A-7 engine had exhausted all of its propellant and shutdown, the stack still climbing while waiting for the proper altitude to ignite the second stage.

SIMULATION. The Alcor stack coasts after MECO.

At 75000 meters altitude the second stage separated from the first and the Attitude Control System started the ullage process, and as usual three seconds later the AJ10 ignited.

SIMULATION. The second stage separates from the first, the ACS is clearly visible.

SIMULATION. The AJ10 is ignited and will burn for its full duration.

The fairings were discarded at 110km altitude when the atmospheric drag had become negligible.

SIMULATION. Fairing separation successful.

After 115 seconds the AJ10 shutdown and the ACS was activated to achieve three-axis stabilization in the coast phase. The intensive overhaul and improvement work that had been done on the hypergolic rocket engine had paid off in the end.

SIMULATION. SECO has occurred and the rocket coasts once again.

At twenty seconds from apogee the Attitude Control System started the spin-up process which imprinted a spin to the stage of 45 rpm.

SIMULATION. The ACS spin-stabilizes the stage. Also a great picture of the second stage.

Just five seconds before reaching apogee the three Baby Sergeants were ignited and the third and final stage separated. If all went well Ethereal 1 would be in orbit less than 10 seconds later.

SIMULATION. The 3 Baby Sergeants firing. Unfortunately a glitch in the simulation software messed up the plume's position.

Indeed, all went well.

SIMULATION. Ethereal 1 sails onwards in the Earth's termosphere.

The telemetry received from the vehicle and satellite indicated that it had indeed reached orbit, but the confirmation would only be obtained 124 minutes later, as the probe made a full circle around the Earth and once again its signal was received by ground stations in the US.

Ethereal 1 was in orbit.

The deafening silence that had pervaded the mission control room at Cape Canaveral in the last two hours rapidly became a mixture of joy, cheers and laughter. Telemetry analysis later confirmed the specifics of the orbit: Ethereal 1 had a perigee of 310km and an apogee of 3431km, an orbital inclination of 28.631° and an orbital period of 2 hours 4 minutes and 6 seconds.

The news of the successful launch was a shot heard around the globe. It made front page on every possible media outlet, and brought worldwide attention to the International Rocket Society. The Soviet Union congratulated the IRS, the US and the UK for their successful launch and confirmed the orbit of the satellite. The Soviets again stated that they would soon follow suit by launching a probe in orbit themselves.

Apart from the huge publicity and financial gains that the IRS made, several scientific results were also obtained. The most intriguing one was the data received from the Geiger counter. At altitudes below 1000km the counter worked as expected, yet above that it seemed to stop working, only to resume its operation as it approached perigee again. This weird phenomenon remained unexplained for the moment.

Ethereal 1’s battery finally died out on February 16 1957 after 105 days of continuous operation, yet, due to the satellite high apogee and perigee, it remains in orbit to this day, and, although originally expected to have an orbital life of around 2000 years, due to solar radiation pressure this slipped to “only” 240 years, with reentry set to occur in 2196.

-If required, use the "Stroke" layer style to better define the outer edges (especially useful if the rocket is mostly white);

-To get that "worn" effect, I simply use paper textures downloaded from the internet, put them as top layer and then using the layer "Blending modes" to make it fit to perfection, Difference is the one I usually use but it really depends.

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The people and press were of course more than enthusiastic about the successful launch of Ethereal 1, but the IRS staff knew the satellite was just a step, not the ultimate goal, and there was still much to do. Preparations for a second satellite launch, named Ethereal 2, began on December 27 1956.

Not many days later, on January 4 1957, the Soviets orbited a probe of their own, nicknamed Sputnik 1 (literally Satellite 1). The IRS and western governments congratulated themselves with the USSR, but the news came as a shock to the western people and press. Indeed, they had believed the Soviet Union to be so technologically backwards that it would never have the capability to realistically launch a satellite in the foreseeable future. They underestimated their opponent. They were proven very wrong.

The IRS had known the capabilities of the Soviet space program for a very long time, indeed, they had believed the USSR would be the first nation to orbit a probe, and were it not for the fortuitous coincidences that had expedited the manufacture of Ethereal 1, this would have been a very likely possibility.

The next step in this race to space was to get something to the Moon, hopefully before the Soviets. Unfortunately, the current launch vehicles did not possess the capability for such a feat, and a more powerful one would still require at least a year of R&D before being deemed safe for launch. Therefore, the IRS decided to continue with the Earth satellites for the time being, until the new LV became available.

Educational image of Ethereal 2 released for the general public.

Ethereal 2 was a 54 kg probe, and it had a very different design from that of Ethereal 1. The elongated shape of the earlier satellite had been dropped in favor of a spherical one with a diameter of 20 inches, and every component of the probe was contained inside of the sphere, instead of being divided into several compartments.

The satellite carried a series of experiments. A more powerful Geiger-Müller tube was fitted, since it was thought that the lighter one on Ethereal had likely been oversaturated by an unknown source of radiation. A small TV camera had been fitted inside the satellite to allow for low-quality photographs to be taken. The micrometeorite microphone was retained, but the erosion gauges had been moved to the sides of the solar panels (more on those later). The barometer/thermometer layout was still the same as the previous satellite, only it had been modified to fit in the new satellite shape.

The real innovation that Ethereal 2 brought were the six 0.05m2 solar cells, capable of outputting a maximum 3.15 Watts of power each. This, coupled with the batteries on board, would enable the satellite to operate for a much longer time than its predecessor. Two antennas identical to those mounted on Ethereal 1 were fitted on the satellite body for transmission.

The heavier weight of the payload called for the X-242 third stage to be used in place of Ethereal 1’s clustered Baby Sergeants.

The launch was scheduled for mid-February.

Incredibly however, Ethereal 2 wouldn’t be the third satellite to reach orbit. Sputnik 2 was launched by the Soviets just a month after the first, on February 3 1957. It was a very heavy satellite, and carried the first living being to orbit: a dog called Laika.

Just 10 days after Sputnik 2, on February 13, Ethereal 2 was go-for-launch.

Image 19570213A: The Ethereal 2 stack taken some time before launch. Photo courtesy of the CBS' Danny Brewer.

The launch took place at around 15 in the afternoon, and a crowd of observers had gathered, although not as large as the one for Ethereal 1.

The first stage burn was almost perfect, but a small problem in the fuel valves meant that the burn was terminated 1.1 seconds before nominal. It would have little effect on the whole flight however.

SIMULATION. The stacks climbs through the clouds over Cape Canaveral AFB.

The second stage was separated at around 75km as usual, and ignition of the AJ10 went smoothly.

SIMULATION. The decoupler fires.

SIMULATION. The second stage fully separates and ignites.

The fairing were separated without incident when the pressure was low enough.

SIMULATION. Fairing separation.

The Alcor stage functioned perfectly until propellant exhaustion.

SIMULATION. The AJ10 engine keeps burning its propellant.

The X-242 was spin stabilized by the Alcor’s Attitude Control System to 70 rpm.

SIMULATION. The second and third stage coast to apogee.

22.5 seconds before apogee the third stage was separated and ignited…

SIMULATION. The third stage is firing.

… and 45 seconds later Ethereal 2 was in a 327x4573km orbit, at 28.836° inclination and with an orbital period of 2h 17m 26s.

SIMULATION. Ethereal 2 is in orbit and will remain there for the foreseeable future.

Ethereal 2 was another success for the International Rocket Society. It took a series of photographs of the Earth, the first ever from orbit, one of which is shown right below:

Image 19570213C: Photograph of Florida and Cuba taken by Ethereal 1 after one orbit.

But the most important bit of data that was obtained from the satellite were not the photographs, but rather the results of the Geiger counter. The smaller one carried by Ethereal 1 had indeed been saturated by the extreme radiation found above 1000km from the Earth, which was instead measured correctly by the counter aboard Ethereal 2. There was no interruption of this radiation field even at the satellite’s apogee. It was believed that a sort of “belt” existed around the Earth, and it was named after James Van Allen, who had devised the Geiger tube on both Ethereal 1 and 2.

Ethereal 2 would function continuously for 7 years, before the solar cells degraded enough to not be able to recharge the batteries fast enough. However, it still remains in orbit to this day.

Despite all the scientific discoveries its satellites had made, the IRS wanted to demonstrate the possible uses of probes orbiting the Earth. To do so, they planned to launch an atmospheric analysis satellite that could monitor the Earth’s atmosphere, in preparation for an eventual full-blown weather satellite that could help better predict the weather.

Ethereal 3 was a 77 kg satellite, very similar to Ethereal 2, having the same spherical satellite bus. The solar cells were of a larger size, and were also positioned towards the front end of the satellite. The scientific loadout was also very similar, but emphasis was placed on more powerful atmospheric analysis experiments, which increased the probe’s weight. Larger batteries were also outfitted, while the antennas were the exact same as Ethereal 2.

The launch date for Ethereal 3 was set for April 9, 1957.

The rocket took off at 10:23 in the morning.

Image 19570409A: The Ethereal 3 stack is go for launch. Photo courtesy of the BBC.

The first stage burned completely, the valve issue found on the previous launch having been solved.

SIMULATION. The Alcor rocket climbs through the lower atmosphere without issue.

The second stage separated and put the payload into the semi-final trajectory

While the launch of Ethereal 3 had been a success, limited data was obtained due to the satellite’s highly eccentric orbit. Plans for subsequent weather satellites had to account for the eccentricity, or orbit at lower altitudes. Unfortunately, the solar cells on the probe failed after a year of operation, abruptly putting an end to its mission. The satellite, however, is still in orbit.

Nevertheless, the incredible and repeated successes of the IRS had attracted the attention of numerous nations. A series of talks were held, and the future of the IRS was decided.

The International Rocket Society had a much more limited scope than what envisioned at the talks. Therefore, on April 14 1957, just days after Ethereal 3 was put into orbit, the IRS was disbanded, to be reformed into the International AeroSpace Research and Development Agency, or IASRDA for short. The Agency encompassed the nations of the US, the UK, France, Italy, West Germany, Canada, the Netherlands, Spain and Norway for the moment, but in the future many more countries would join the effort.

A true Space Agency was born on that historic day.

Logo of the International AeroSpace Research and Development Agency since 1957.